触发器

创建触发器:
delimiter $$
create trigger ranran
 before update(after update|before insert|after insert) on user for each row
 begin
    insert into wuxiaoxiao(note) values("before update!");
    或者(insert into wuxiaoxiao(note) values(new.user_name);)
 end;
 $$
删除触发器:
drop trigger trigger_name;
查看触发器:
show triggers;